Flexural behavior evaluation of a foam core curved sandwich beam

In this study, curved sandwich beams (CSBs) with glass fiber-reinforced polymer (GFRP) and polyethylene terephthalate (PET) foam core were initially fabricated. Experiments in three-point bending were then performed to understand the flexural behaviors including failure modes, load-bearing capacities, and load–displacement curves. The effects of various geometrical parameters including facesheets and core thicknesses, two different types of cores, and curvature radius were clarified. It was found that the utilization of PET foam in CSBs resulted in a prevention of core shearing failure and a gradual decrease in load–displacement response. Moreover, the results showed that the ultimate load-bearing capacity and stiffness of the CSBs decreased by 17.7 % and 61.8 %, with a curvature decreased from 1500 to 300 mm, respectively. An analytical model was performed to accurately estimate the experimental failure modes and load-bearing capacities of CSBs. Failure maps were also developed to investigate the various failure modes caused by different geometric parameters of curved sandwich beams. The failure maps offer valuable guidance for the design of lightweight structures.